CHAPTER IV. 



THE BILE. 



INTRODUCTORY OBSERVATIONS, 



IN the preceding chapters of this book the various secretions 

 have been considered in connection with the general physiology of 

 the organs which produce them, some account having also been 

 given of the structure of these. In the case of the bile, however, a 

 different course will be followed, for reasons which will presumably 

 commend themselves to the readers of a book which aims at a 

 thorough chemical treatment of the processes of the animal economy, 

 considered, however, from the point of view of the philosophical 

 biologist. 



In this volume we shall consider the general chemical composi- 

 tion of the bile, its proximate principles and their transformations, 

 and the probable part played by the bile in the intestine, inde- 

 pendently of the general physiology of the organ which produces it. 



The bile is to be looked upon as a comparatively insignificant 

 by-product 1 resulting from the extremely complex and diverse 

 chemical operations which have their seat in the liver, the largest 

 and, perhaps, the most important of all the glands of the body. 

 This by-product furnishes as little insight into the great operations 

 which are conducted in, and by, this great chemical factory, the 

 liver, as might be obtained of the nature and magnitude of the 

 operations carried on in extensive chemical works, were we only 

 permitted to study the chemical composition of a drain into which 

 some alone of the waste products of the works were regularly dis- 

 charged. Doubtless this study might throw some light on the opera- 

 tions of the factory and would, certainly, be necessary to their com- 

 plete investigation, which, however, would only be possible when we 

 were placed in a position to examine the raw materials entering, the 

 structure and relative relations of the various parts of the factory, the 

 nature and mutual dependence of the various chemical operations 

 carried on within its precincts, no less than all the products resulting 



1 ' The human liver weighs from 1500 to 2000 grms., and produces in twenty-four 

 hours about 400 to 600 grms. of bile. The parotid, which only weighs from 24 to 

 30 grms., produces in the same time from 800 to 1000 grms. of secretion ' (Bunge). 

 The comparison quoted indicates how subordinate must be the part played by the 

 bile in respect to the general functions of the liver. 



